Condensed Consolidated Comprehensive Income Statements - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Statement of Comprehensive Income [Abstract]
Net income	$ 896	$ 530	$ 3,144	$ 2,102
Other comprehensive income (loss) before taxes:
Foreign currency translation	(13)	32	(35)	87
Unrealized (losses) gains on available-for-sale securities	(2)		(8)	5
Defined benefit plans	0	0	0	0
Pension costs included in salaries and benefits	5	5	15	14
Total defined benefit plans	5	5	15	14
Change in fair value of derivative financial instruments	10	(1)	60	(9)
Interest (benefits) costs included in interest expense	(3)	4	(5)	17
Total change in fair value of derivative financial instruments	7	3	55	8
Other comprehensive (loss) income before taxes	(3)	40	27	114
Income taxes related to other comprehensive income items	2	15	15	44
Other comprehensive (loss) income	(5)	25	12	70
Comprehensive income	891	555	3,156	2,172
Comprehensive income attributable to noncontrolling interests	137	104	421	360
Comprehensive income attributable to HCA Healthcare, Inc.	$ 754	$ 451	$ 2,735	$ 1,812